Twenty people onboard a Singapore Airlines flight that hit severe turbulence on Tuesday are currently under treatment in intensive care facilities, Bangkok's Samitivej Hospital said in a statement on Wednesday.

The hospital said a total of 58 people were still under treatment at multiple medical facilities, and 27 had been discharged.

The scheduled London-Singapore flight was diverted to Bangkok after the plane was buffeted by turbulence that flung passengers and crew around the cabin, slamming some into the ceiling. One passenger died of a suspected heart attack.